Yeah, the blue one is a coupe from the factory. The black one is a vert that has an aftermarket hard top in place of the convertible top. They both have the same engine/tranny/rear. I'm thinking of doing the same top on my car, not sure if I wanna lose the vert just yet though. Personally, I think the convertibles with the aftermarket tops look better than the normal coupes.
BTW, that black car goes 150+ in the 1/4!! Has to be my favorite Viper.